The kind of hybrid you're after kind of happens in close combat in Age of Sigmar already; however it can be somewhat messy because one player is still getting to move around their whole army for a turn and moving in itself can be a very major part of the game itself (or at least should be in most cases).
Now as you're new to the game it could be that your deployment was poor and you basically left yourself open to taking heavy casualties early in the game, whilst deploying a little differently might have given you more protection without hindering your early game performance*
You aren't wrong,
GW's style of high damage output (high lethality) coupled to whole army turns does leave it wide open to issues that you've experienced (its nothing new, people have argued over it for decades now).
However there are tactics and methods you can use to help mitigate it.
Deploying differently;
Ensuring that the board actually has line of sight blocking terrain features
Using reinforcement/droppod/etc.. abilities so that some of your army is held in reserve and pulls in when needed
Learning to take hits and roll with them in the game - easy to say harder to master.
In the end if you want to try a full
AA system you could see if your club plays or is open to playing One Page Rules, which has rules systems for all the
GW armies in a fully Alternate Activation system.
https://www.onepagerules.com
If not then I'd still encourage you to play more
40K games and each time review what happened; what went wrong; what went right and to learn from those experiences.
*Something I suffer with is hiding up too early too much and surviving the game, but ending up losing control of the board because my units take longer to come out of cover, into the open to do things - by which point my opponent has secured the middle and dominated the game and whittles down my army